1. Field of the Invention
This invention relates to a method of and an apparatus for inserting slot insulators such as wedges and layer insulators together with coils into slots of a stator core of a dynamoelectric machine.
2. Description of the Prior Art
The prior art has provided medium and small size electric motors comprising a stator core employing a concentric single-layer winding pattern in which a single layer of coil is inserted in each slot of the stator core. Publication No. 61-45732 (1986) of Japanese examined utility model registration application discloses an apparatus for inserting the coil in each slot and shaping the inserted coil in the case of such a single-layer winding pattern. In the disclosed apparatus, a coil inserting jig and a coil shaping jig are equipped separately from each other. A core holder provided for setting a stator core at a predetermined location is moved along a U-shaped movement path so that coil insertion and shaping are performed. Furthermore, the coil inserting jig and the coil shaping jig are disposed in parallel on a table which is moved transversely. The core holder is moved in the directions perpendicular to the directions in which the table is moved.
On the other hand, publication Nos. 4-156245 (1992) and 4-178133 (1992) of Japanese unexamined patent applications. each disclose concentric and lap double-layer winding patterns. The size of the wedge differs from that of the layer insulator in these winding patterns. Accordingly, the wedges and the layer insulators cannot be inserted by a single apparatus having the above-described coil inserting and shaping mechanism for the concentric single-layer winding pattern when the coils, slot insulators and the wedges are inserted into the core slots so as to form the concentric or lap double-layer winding. This poses a problem.